fix: build image URL regexes at call time, not module load time

test/image-downloader.test.ts

@@ -20,8 +20,14 @@ describe("downloadCommentImages", () => {
   let fsMkdirSpy: any;
   let fsWriteFileSpy: any;
   let fetchSpy: any;
+  let savedServerUrl: string | undefined;
 
   beforeEach(() => {
+    // Pin GITHUB_SERVER_URL so tests pass regardless of runner environment.
+    // The image-downloader reads process.env directly at call time.
+    savedServerUrl = process.env.GITHUB_SERVER_URL;
+    process.env.GITHUB_SERVER_URL = "https://github.com";
+
     // Spy on console methods
     consoleLogSpy = spyOn(console, "log").mockImplementation(() => {});
     consoleWarnSpy = spyOn(console, "warn").mockImplementation(() => {});
@@ -36,6 +42,13 @@ describe("downloadCommentImages", () => {
   });
 
   afterEach(() => {
+    // Restore GITHUB_SERVER_URL
+    if (savedServerUrl !== undefined) {
+      process.env.GITHUB_SERVER_URL = savedServerUrl;
+    } else {
+      delete process.env.GITHUB_SERVER_URL;
+    }
+
     consoleLogSpy.mockRestore();
     consoleWarnSpy.mockRestore();
     consoleErrorSpy.mockRestore();